J J Kapsberger
Well-known
I have used it (in the distant past) as powder, but for some reason I thought I'd seen a liquid version on the shelves of my local retailer. Must have been hallucinating.
Your mention of it as a liquid struck a chord, which is why I asked. I seem to recall a developer available in both powder and liquid form. But I guess I'm the one hallucinating. Or perhaps the Ilford liquid developer is called 'this' and it has the same characteristics as 'that', a powder developer.